Advancing Early Breast Cancer Diagnosis and Ki-67 Expression Prediction With Ultrasound Viscoelastography: Based on Peritumoral Assessment.

Background: Breast cancer is the most common invasive malignancy in women. Ultrasound viscoelastography may improve non-invasive diagnosis, but the clinical relevance of peritumoral viscoelastic parameters (VPs) and their correlation with Ki-67 remain unclear. This study explores these associations. Methods: A prospective study enrolled 256 breast masses (156 malignant, 100 benign). Patients underwent conventional ultrasound and viscoelastography. VPs were acquired within masses (A), peritumoral shells (Shell1: 1 mm, Shell2: 2 mm, Shell3: 3 mm), and combined regions (A' = A + Shell). Quantitative metrics included elasticity (V/1 E, V/0 E), dispersion coefficient (V/1 D), viscosity coefficient (V/0 V), and their maximum (Max), minimum (Min), mean(Mean), and standard deviation (SD) values. Diagnostic performance was evaluated by analyzing the receiver operating characteristic (ROC) curve and calculating the area under the curve (AUC), followed by logistic regression. VPs were compared between high/low Ki-67 groups. Results: The AUCs of peritumoral VPs exceeded those from masses. V/1 D showed higher AUC than V/0 V and elasticity values, with Shell3 V/1 D SD having the highest AUC (0.840). The diagnostic efficacy of the peritumoral viscoelastic model surpassed that of the single elasticity parameter model, with 89.1% sensitivity, 73% specificity, 82.8% accuracy. Key variables included Shell3 V/1 D and Shell3 V/0 E. Shell1 V/0 V Max was significantly higher in high versus low Ki-67 expression groups ( Conclusion: The viscoelastic model improves diagnostic accuracy by quantifying peritumoral biomechanics, and certain VPs may predict Ki-67 expression. Peritumoral VPs show potential as novel non-invasive imaging biomarkers for early breast cancer evaluation.